U.S.-bound shipments increased nearly 7.7% across all of the nation’s seaports in January, according to research by Panjiva Inc. The increase was largely driven by post-holiday restocking by U.S. retailers and manufacturers, as well as early shipments by Chinese companies ahead of a two-week Lunar New Year factory shutdown.

The Ports of Los Angeles and Long Beach imported 747,488 loaded 20-foot equivalent units last month, just a 4.6% increase over January 2017, while imports declined 6.6% to 75,136 loaded TEUs at Oakland’s port in January.

Economists say the biggest factors behind the import boost are a robust economy, and the U.S.’s continued reliance on international trade. Consumers and businesses continue to buy goods made overseas, primarily from China, where January’s import shipments rose 10.3%.

Last year was a record-setting year for import shipments to the U.S., as numbers were up 4.1% from 2016’s, resulting in a trade deficit of $566 billion, the widest in nine years.